EP0677503B1

EP0677503B1 - Process for producing 1,1,1,3,3-pentafluoropropane

Info

Publication number: EP0677503B1
Application number: EP94903065A
Authority: EP
Inventors: Seiji Yodogawa Works Of Takubo; Hirokazu Yodogawa Works Of Aoyama; Tatsuo Yodogawa Works Of Nakada
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 1992-12-29
Filing date: 1993-12-24
Publication date: 1999-04-07
Anticipated expiration: 2013-12-24
Also published as: WO1994014736A1; RU2114813C1; CA2152940C; EP0677503A4; DE69329399T2; EP0677503A1; KR960700211A; RU95114401A; DE69329399D1; AU5716194A; DE69324377D1; DE69324377T2; ES2131669T3; AU669772B2; US5763705A; KR0171486B1; KR100205618B1; CA2152940A1; EP0844225A1; JP3248184B2

Abstract

A method of producing 1,1,1,3,3-pentafluoro-2-halogeno-3-chloropropane characteriized by fluorinating a halogenated propene indicated by the general formula I: <CHEM> (provided that in the general formula, X and Y are respectively Cl or F) with hydrogen fluoride in the presence of antimony trihalogenide and/or antimony pentahalogenide in a liquid phase, wherein the hydrogen fluoride is present in the reaction system in a mole ratio of or over five times that of antimony trihalogenide and/or antimony pentahalogenide. This process can provide the desired product at low cost in high yields on an industrial scale.

Description

This invention relates to a method of producing 1,1,1,3,3-pentafluoropropane which is a useful compound usable as a substitute for CFC and HCFC which are utilized for a cooling medium, a blowing agent or a cleaning agent and is particularly useful as a urethane blowing agent.

Prior art

As a method of preparing 1,1,1,3,3-pentafluoropropane, a reductive reaction with hydrogen wherein 1,2,2-trichloropentafluoropropane is used as a raw material is known (U.S. P.2,942,036).
However, this reaction is not suitable for industrial use due to a low yield and the generation of 2-chloropentafluoropropene and 1,1,3,3,3-pentafluoropropene which are not reduced enough.
On the other hand, 1,1,1,3,3-pentafluoro-2-halogeno-3-chloropropane is useful itself as an intermediate of medicines or agricultural chemicals and is a useful compound for the industrial use which can be conducted to hydrofluorocarbon as a substitute for HCFC and CFC which are used as various cooling mediums, blowing agents or cleaning agents, by fluorination or reduction and which can be conducted to monomers of various kinds of resins by dehydrochlorination. Especially, 1,1,1,3,3-pentafluoro-2,3-dichloropropane can be useful as a raw material of 1,1,1,3,3-pentafluoropropane.
Until now, a method of fluorinating propene halogenide with HF in a liquid phase under the presence of an antimony halogenide is known. For example, E. T. McBee et al. obtained 1,1,1,3,3-pentafluoro-2,3-dichloropropane by fluorinating 1,1,1-trifluoro-2,3,3-trichlorcpropene with HF under the presence of an antimony catalyst (J. Am. Chem. Soc. 70, 2023, (1948)).
However, because 1,1,1-trifluoro-2,3,3-trichloropropene, HF and antimony catalyst as raw materials are supplied at once to a reactor before reaction, not only this reaction needs a high reaction temperature of 250 °C, but also the yield of 1,1,1,3,3-pentafluoro-2,3-dichloropropane is so low as to be 50%, thus this reaction cannot be used industrially.
Besides, 1,1,1,2,3,3-hexachloropropene is useful as an intermediate of various medicines or agricultural chemicals and is a useful raw material by which an intermediate of various fluorine compounds can be synthesized by fluorinating chlorine of this propene with HF. Especially, it is useful as a raw material of 1,1,1,3,3-pentafluoro-2,3-dichloropropane (HCFC 225da).
Generally, 1,1,1,2,3,3-hexachloropropene can be synthesized by dehydrochlorination of 1,1,1,2,2,3,3-heptachloropropane. 1,1,1,2,2,3,3-heptachloropropane being a raw material is an economical industrial raw material which can be easily synthesized from chloroform and tetrachloroethylene as economical industrial raw materials.
Hitherto, there is known a method of synthesizing 1,1,1,2,3,3-hexachloropropene by dehydrochlorination of 1,1,1,2,2,3,3-heptachloropropane with alkali metal hydroxide like KOH in an alcohol solvent (J. Am. Chem. Soc., 63,1438 (1941)).
However, because of using alcohol as the reaction solvent, this method needs to filtrate the alkali metal chloride produced after the reaction and then separate the product from alcohol by the use of an operation such as distillation.
And, it is also known that by passing through a reacton tube heated around 400°C, it can be obtained from 1,1,1,2,2,3,3-heptachloropropane, but this reaction requires a high temperature and the use of expensive metal for the material of the reaction tube because of the generation of HCl in the reaction.
WO-A-90/08 753 discloses a process for producing a hydrogen- and chlorine-containing 2,2-difluoropropane.

Object of the invention

The object of this invention is to provide a method being able to produce 1,1,1,3,3-pentafluoropropane (HFC 245fa) enough in high selectivity in which any problems as mentioned above do not occur.

The constitution of the invention

As a result of eager study by the inventors regarding a method of producing 1,1,1,3,3-pentafluoropropane to solve the above-mentioned problems, they found that the objective product can be obtained at high yield when a reductive reaction with hydrogen (catalytic reduction) was performed by the use of 1,1,1,3,3-pentafluoro-2,3-dichloropropane as a raw material under the presence of a noble metal catalyst such as palladium in a gaseous phase, having completed the present invention.
That is, the present invention provides a method of producing 1,1,1,3,3-pentafluoropropane at high selectivity of not less than 80% by hydrogen reduction reaction using 1,1,1,3,3-pentafluoro-2,3-dichloropropane as a raw material, in a gaseous phase system in the presence of a noble metal catalyst such as palladium, particularly at a temperature from 30 to 450°C.
In the present invention, it is particularly important that the hydrogen reduction is carried out with the noble metal catalyst in a gaseous phase. For the gaseous phase reaction system of the gaseous phase reaction, e.g. a fixed bed-type gaseous phase reaction and a fluidized bed-type gaseous phase reaction can be adopted.
As the noble metal of the noble metal catalyst, e.g. palladium and platinum can be nominated and from the point of a selectivity of the reaction, that is, from the point of the small amount of by-product palladium is preferable. These are desirably carried on at least one kind of carriers selected from active carbon, silica gel, titanium oxide and zirconia.
Besides, the particle diameter of the carrier does not scarcely affect the reaction, however, it is desirably 0.1 to 100 mm.
The carrying concentration can be applied in a wide range from 0.05 to 10 % (by weight), but it is usually recommended to be from 0.5 to 5 %.
The reaction temperature is usually from 30 to 450 °C, preferably 70 to 400°C.
In the reductive reaction with hydrogen of 1,1,1,3,3-pentafluoro-2,3-dichloropropane, the ratio of hydrogen to the raw material can be varied widely. But usually, at least a stoichiometric amount of hydrogen is used for the hydrogenation. Hydrogen of rather more than the stoichiometric amount, for example, 8 mole or more than 8 mole to the total mole of the starting material can be used.
The reaction pressure is not particularly limited and the reaction can be carried out under pressure, reduced pressure or normal pressure, but preferable under pressure or normal pressure because the equipment is complicated under reduced pressure.
The contact times are usually in the range of 0.1 to 300 seconds, particularly in the range of 1 to 30 seconds.
The raw material, 1,1,1,3,3-pentafluoro-2,3-dichloropropane is a known compound and can be obtained by the reaction of fluorinating 1,1,1-trifluoro-2,3,3-trichloropropene (E. T. McBEE, ANTHONY TRUCHAN and R. O. BOL T, J. Amer. Chem. Soc., vol 70, 2023-2024 (1948)).
In a preferred embodiment of the above described method of producing 1,1,1,3,3-pentafluoropropane, the nobel metal catalyst comprises palladium to which at least one kind of element selected from zirconium and vanadium is added.
In the above mentioned preferred embodiment, the particle diameter of the carrier, the carrying concentration, the reaction temperature, the ratio of hydrogen to the raw material, the reaction pressure and the contact times are as mentioned above.
In another embodiment, the production method of the present invention includes the following steps
(1) reacting 1,1,1,2,2,3,3-heptachloropropane with an aqueous solution of an alkali metal hydroxide in the presence of a phase transfer catalyst to obtain 1,1,1,2,3,3-hexachloropropene.
(2) fluorinating said 1,1,1,2,3,3-hexachloropropene with hydrogen fluoride in the presence of antimony trihalogenide and/or antimony pentahalogenide in a liquid phase, wherein the hydrogen fluoride is present in the reaction system in a mole ratio of or over five times that of antimony trihalogenide and/or antimony pentahalogenide, to obtain 1,1,1,3,3-pentafluoro-2,3-dichloropropane, and
(3) reacting said 1,1,1,3,3-pentafluoro-2,3-dichloropropane with hydrogen to conduct a hydrogen reduction under the presence of a noble metal catalyst in gaseous phase.
In the above method of the invention, it is known that antimony chloride added to the reaction system is partially fluorinated into SbClxFy (x+y=5) in the presence of HF, and the inventors found that in the case of using it as catalyst for the fluorination of a compound having hydrogen or double bond capable of being chlorinated such as 1,1,1,2,3,3-hexachloropropene, the more the fluorine content, the more quickly the reaction of fluorinating is carried out to inhibit the formation of chlorinated product being a by-product of the reaction.
There was found that by coexistence of HF which is excessive in amount to the added antimony trihalogenide and / or antimony penta halogenide, the fluorine content of antimony trihalogenide and / or antimony pentahalogenide can be kept high and the addition reaction can be promoted to synthesize 1,1,1,3,3-pentafluoro-2,3-dichloropropane at high selectivity.
The amount of HF supplied into a reactor consists of a consumption amount of HF added by the lost amount accompanied with the product. That is, the amount of HF in the reaction system is thus kept constant. However, the variation of the range permissible in the capacity of the reactor is allowed if the excess rate of HF can be maintained. Besides, all of the required amount of HF can be also charged into the reactor before the reaction.
The introduction amount per an hour (supply rate) of 1,1,1,2,3,3-hexachloropropene charged into the reactor must be lesser to fluorinated-chlorinated antimony added to the system, but the lesser amount is not desirable due to a decrease of the production amount per the capacity of the reactor.
But if the amount is so large, the fluorine content of fluorinated-chlorinated antimony decreases so that the selectivity is lowered although the reaction proceeds. That is, the introduction amount of 1,1,1,2,3,3-hexachloropropene to the charged fluorinated-chlorinated antimony is usually set not more than 100 times mole / hr and not less than 2 times mole / hr. It is desirable to be set not more than 50 times mole / hr and not less than 5 times mole / hr.
The reaction advances whenever the reaction temperature is 40 °C or over, but in this case, if the supply amount of 1,1,1,2,3,3-hexachloropropene to the charged fluorinated-chlorinated antimony is lesser, the selectivity decreases.
A high reaction temperature is favorable in points of the productivity and the selectivity, but a reaction pressure should be kept high according to the reaction temperature. Because keeping the reaction pressure high raises the cost of equipment, the reaction is practically desirable to be carried out in the range from 50 to 150 °C.
Besides, the reaction pressure is elevated according to the reaction temperature, and an adequate value can be selected in the range from 2.94 bar (3 kg/cm²) to 29.4 bar (30 kg/cm²) in order to separate HF and the product. And, the object can be obtained at high yield with keeping the reaction pressure constant, by slowly supplying 1,1,1,2,3,3-hexachloropropene as a raw material and hydrogen fluoride into the reaction system and by selecting the produced 1,1,1,3,3-pentafluoro-2,3-dichloropropane.
An increase in the amount of HF coexisted with fluorinated-chlorinated antimony in the reaction system does not affect the selectivity of the reaction, but it lowers the productivity per reactor capacity. In the case of a small amount, although the reaction advances, the supply amount of 1,1,1,2,3,3-hexachloropropene must be small owing to avoid a decrease of the selectivity. In practice, the reaction should be carried out in which the amount of hydrogen fluoride to fluorinated-chlorinated antimony is five times or more mole of the latter, preferably not more than five hundreds times. More desirably, HF of fifty times or over and two hundreds times or less moles is coexisted.
Still more, in addition to the above described ones, antimony trihalogenide and antimony pentahalogenide usable in the invention are a mixture of SbF₃ and SbCl₅, SbF₃ with SbCl₂F₃ as a part converted by Cl₂ therefrom.
In general, in step (1) of the above described production method, an ionic compound like the alkali metal hydroxide is not soluble in said heptachloropropane. Therefore, the reaction is generally carried out using a compatible solvent like alcohol. However, this method needs to separate the used reaction solvent from the produced object after the reaction. Besides, it might be considered to perform the reaction using an aqueous solution of alkali metal hydroxide in a two-phase system, but the reaction is generally so slow that it often needs violent conditions in a two-phase system.
However, there was found that when according to the invention the reaction in step (1) is carried out using the aqueous solution of alkali metal hydroxide in a two-phase system under the presence of the phase transfer catalyst, particularly the below-mentioned tetraalkylammonium salt or tetraalkyl phosphonium salt, it proceeds quickly in a mild condition.
As the cation of tetraalkyl ammonium salt used in the reaction, e.g. benzyltriethyl ammonium, trioctylmethyl ammonium, tricaprylmethyl ammonium, and tetrabutyl ammonium can be mentioned.
As the cation of tetraalkyl phosphonium salt, e.g. tetrabutyl phosphonium and trioctylethyl phosphonium can be mentioned.
The anion constituting the salt with the above-mentioned cation is not limited, but e.g. chloride ion and hydrogensulfate ion can be cited in general.
However, the above-mentioned ones are nothing but examples and do not restrict the kind of the catalyst.
As the alkali metal hydroxide usable in the above-mentioned reaction, e.g. NaOH and KOH can be exemplified. The concentration of the aqueous solution of this alkali metal hydroxide is not limited, however, it may be from 5 to 50 %, preferably from 20 to 40 % for the reaction.
These aqueous solutions can be reused after removing the produced alkali metal chloride, e.g. by way of precipitation or filtration and adding the alkali metal hydroxide again.
The reaction is carried out in a two-phase system to generate phase separation easily so as to obtain an objective crude product of 1,1,1,2,3,3-hexachloropropene. The obtained crude product can be easily refined by distillation and the used catalyst and the unreacted heptachloropropane can be recovered.
The reaction is usually carried out at a temperature from the room temperature to 80 °C, desirably from 40 to 60°C.
And, 1,1,1,2,2,3,3-heptachloropropane as a raw material can be obtained by reacting tetrachloroethylene with chloroform in the presence of a Lewis acid catalyst like aluminium chloride (See JP-A-118333/1986).
Concerning the production method of the invention as above-mentioned, the products obtained in steps (1) and (2) are usable as follows:
First, 1,1,1,2,3,3-hexachloropropene as a raw material which is obtained in step (1) can be led to 1,1,1,3,3-pentafluoro-2,3-dichloropropane by the reaction of step (2), then this can be led to 1,1,1,3,3-pentafluoropropane by the reaction of step (3). The object can be obtained at high yield through this series of reactions from a cheap raw material easily available, which is superior in economy.
In this case, 1,1,1,2,3,3-hexachloropropene obtained by the reaction of step (1) can be led to 1,1,1,3,3-pentafluoro-2,3-dichloropropane by the reaction of step (2), then this can be taken out as a product. In this process, there is given an advantage that the obtained product can be used as an intermediate of medicines or agricultural chemicals or an intermediate of monomer of resins.
And, 1,1,1,3,3-pentafluoro-2,3-dichloropropane as a raw material obtained by the reaction of step (2) can be led to 1,1,1,3,3-pentafluoropropane by the reaction of step (3). This series of reactions brings about an advantage that 1,1,1,3,3-pentafluoropropane which is important for a urethane blowing agent can be produced at high yield.

The possibility of utilizing the invention in industry

Because in the method of the invention the reductive reaction with hydrogen, in which the raw material is 1,1,1,3,3-pentafluoro-2,3-dichloropropane, is carried out in the presence of the noble metal catalyst like palladium catalyst, particularly at a temperature from 30 to 450 °C, 1,1,1,3,3-pentafluoropropane can be produced at high selectivity of 80% or over.
Regarding the embodiment wherein the method includes the above mentioned steps (1) to (3), the invention can offer an industrial production method capable of manufacturing 1,1,1,3,3-pentafluoro-2,3-dichloropropane at low cost and high yield and easily because 1,1,1,2,3,3-hexachloropropene is fluorinated with hydrogen fluoride under the presence of antimony trihalogenide and / or antimony petahalogenide in a liquid phase, wherein the hydrogen fluoride is present in the reaction system in a mole ratio of or over five times that of antimony trihalogenide and/or antimony pentahalogenide.
Besides, in step (1) of this method, 1,1,1,2,3,3-hexachloropropene can be produced at low cost in a manner that can be industrially and easily performed because of reacting 1,1,1,2,2,3,3-heptachloropropane with the aqueous solution of an alkali metal hydroxide under the presence of the phase transfer catalyst.

Embodiments

Hereafter, examples of this invention will be variously explained, however, those can be variously modified on the basis of the technical concept of this invention.

Example 1

20 cm³ of a palladium catalyst carried on active carbon in 0.5 % concentration was filled in a SUS316-made reaction tube having an inside diameter of 2 cm and a length of 40 cm and heated to 250 °C by an electric furnace under nitrogen flow. After reaching a given temperature, the nitrogen gas was replaced with hydrogen gas and this hydrogen gas was flowed for a time.
Next, beforehand gasified 1,1,1,3,3-pentafluoro-2,3-dichloropropane and hydrogen gas were introduced itno the reaction tube respectively at 16.7 cm³/min and 140 cm³/min. The reaction temperature was kept at 250°C.
Produced gases were analyzed by gas chromatography after washed with water and dried by calcium chloride. The result is shown in table-1.

Example 2

A reaction was carried out under the same condition as that of Example 1 except that the flow rates of hydrogen gas and 1,1,1,3,3-pentafluoro-2,3-dichloropropane were respectively at 140 cm³/min and 17 cm³/min, and the reaction temperature was 270 °C. The result is shown in table-1.

example conversion ratio (%) selectivity (%)

1 100 91

2 100 89
According to these results, the objective compound can be obtained at a conversion ratio of 100 % and high selectivity of not less than 80 % by the reaction based on the invention.

Example 3

20 cm³ of a catalyst in which palladium and zirconium were carried on active carbon respectively in concentrations of 0.5 % and 0.25 % was filled in a SUS316-made reaction tube having an inside diameter of 2 cm and a length of 40 cm and heated to 250 °C by an electric furnace under nitrogen flow. After reaching a predetermined temperature, the nitrogen gas was replaced with hydrogen gas and this hydrogen gas was flowed for a time.
Next, beforehand gasified 1,1,1,3,3-pentafluoro-2,3-dichloropropane and hydrogen gas were introduced into the reaction tube respectively at 16.7 cm³/min and 140 cm³/min. The reaction temperature was kept at 250°C.
Produced gases were analyzed by gas chromatography after washed with water and dried by calcium chloride. The result is shown in table-2.

Example 4

A reaction was carried out under the same condition as that of Example 3 except that the flow rates of hydrogen gas and 1,1,1,3,3-pentafluoro-2,3-dichloropropane were changed respectively to 120 cm³/min and 35 cm³/min. The result is shown in table-2.

Example 5

20 cm³ of a catalyst wherein palladium and vanadium were carried on active carbon respectively in concentrations of 0.5 % and 0.25 % was filled in a SUS316-made reaction tube having an inside diameter of 2 cm and a length of 40 cm and heated to 250 °C by an electric furnace under nitrogen flow. After reaching a given temperature, the nitrogen gas was changed with hydrogen gas and this hydrogen gas was flowed for a time.
Next, beforehand gasified 1,1,1,3,3-pentafluoro-2,3-dichloropropane and hydrogen gas were introduced into the reaction tube respectively at 16.7 cm³/min and 140 cm³/min. The reaction temperature was kept at 250°C.
Produced gases were analyzed by gas chromatography after washed with water and dried by calcium chloride. The result is shown in table-2.

Example 6

A reaction was carried out under the same condition as that of Example 5 except for changing the flow rates of hydrogen gas and 1,1,1,3,3-pentafluoro-2,3-dichloropropane respectively to 280 cm³/min and 32 cm³/min. The result is shown in table-2.

example conversion ratio (%) selectivity (%)

3 100 92

4 100 89

5 100 92

6 100 88
According to these results, the objective compound can be obtained at a conversion ratio of 100 % and high selectivity of not less than 80 % by the reaction based on the invention.

Example 7

29.9 g (0.1 mol) of SbCl₅ was charged into a Hastelloy-made autoclave of 500 ml with a condenser and after cooling it 300 g (15 mol) of HF was added thereto. Then, the temperature was slowly raised and the reaction was carried out at 80 °C for 3 hours.
1,1,1,2,3,3-hexachloropropene and HF were added respectively at 0.2 mol/hr and 1.2 mol/hr with keeping the temperature at 80 °C. A reaction pressure was controlled in the range from 8.8 bar (9 kg/cm²) to 10.8 bar (11 kg/cm²) so that the weight of the reactor becomes constant.
During the reaction, hydrogen chloride and product produced were taken out of an upper portion of the condenser, then the product was captured with a dry ice trap after hydrogen chloride was washed with water. On adding 249 g (1 mol) of 1,1,1,2,3,3-hexachloropropene, the reaction was stopped.
After the reaction, the pressure was slowly decreased and the content was selected out. As a product, 190 g of organic substance was obtained.
It was confirmed with GLC (gas-liquid chromatography) that 97 % of the product was the objective 1,1,1,3,3-pentafluoro-2,3-dichloropropane (91 % of the yield). A main by-product was 1,1,1,3-tetrafluoro-2,3,3-trichloropropane being a reaction intermediate and halogenated propane to which chlorine was added was not detected.

Example 9

29.9 g (0.1 mol) of SbCl₅ was supplied to a Hastelloy-made autoclave of 500 ml with a condenser and after cooling it 300 g (15 mol) of HF was added thereto. Then, the temperature was slowly raised and the reaction was carried out at 80 °C for 3 hours.
1,1,1-trifluoro-2,3,3-trichloropropene and HF were added respectively at 0.2 mol/hr and 0.8 mol/hr with keeping the temperature at 80 °C. A reaction pressure was controlled in the range from 9.8 bar (10 kg/cm²) to 11.8 bar (12 kg/cm²).
In the reaction, hydrogen chloride and product produced were selected out of an upper portion of the condenser, then the product was captured with a dry ice trap after hydrogen chloride was washed with water. On adding 199 g (1 mol) of 1,1,1-trifluoro-2,3,3-trichloropropene, the reaction was stopped.
After the reaction, the pressure was slowly decreased the content was selected out. As a product, 198 g of organic substance was obtained.
It was confirmed with GLC that 98 % of the product was the objective 1,1,1,3,3-pentafluroro-2,3-dichloropropane (96 % of the yield).
A main by-product was 1,1,1,3-tetrafluoro-2,3,3-trichloropropane being a reaction intermediate and halogenated propane to which chlorine was added was not detected.

Example 10

A reaction was carried out under the same condition as that of Example 7 except for charging 29.9 g (0.1 mol) of SbCl₅ and 17.9 g (0.1 mol) of SbF₃ in a Hastelloy-made autoclave of 500 ml with a condenser.
As a product, 196 g of organic substance was obtained. It was confirmed with GLC that 98 % of the product was the objective 1,1,1,3,3-pentafluroro-2,3-dichloropropane (94 % of the yield). A main by-product was 1,1,1-tetrafluoro-2,3,3-trichloropropane and a compound with added chlorine was not detected.
According to the above-mentioned results, by the reaction based on the invention 1,1,1,3,3-pentafluoro-2,3-dichloropropane can be produced easily at high yield.

Example 11

285.5 g (1.0 mol) of 1,1,1,2,2,3,3-heptachloropropane and 0.3 g (0.1 mmol) of tetrabutyl ammonium chloride were charged into a round bottom flask of 500 ml with a Dimroth condenser and a dropping funnel.
With keeping it at 40°C and agitating violently, 250 ml of KOH aqueous solution of 20 % concentration was dropped for 1 hour. After the dropping was finished, the agitating was stopped and an organic layer or a lower layer was analyzed. 1,1,1,2,2,3,3-heptachloropropane as a raw material disappeared and the organic layer consisted of only 1,1,1,2,3,3-hexachloropropene.
The reaction solution was transferred to a separatory funnel to separate the organic layer. After washing with a saturated salt solution two times, it was dried with magnesium sulfate to obtain 237 g (95 %) of crude 1,1,1,2,3,3-hexachloropropene.

Example 12

285.5 g (1.0 mol) of 1,1,1,2,2,3,3-heptachloropropane and 0.3 g (0.1 mmol) of tricaprylmethyl ammonium chloride were supplied to a round bottom flask of 500 ml with a Dimroth condenser and a dropping funnel.
With keeping it at 40°C and agitating violently, 250 ml of KOH aqueous solution of 20 % concentration was dropped for 1 hour. After the dropping was finished, the reaction was carried out for 1 hour. Then, the agitating was stopped and a lower organic layer was analyzed. 1,1,1,2,2,3,3-heptachloropropane as a raw material disappeared and the organic layer consisted of only 1,1,1,2,3,3-hexachloropropene.
The reaction solution was transferred to a separatory funnel to separate the organic layer. After washing with a saturated salt solution two times, it was dried with magnesium sulfate to obtain 232 g (93 %) of crude 1,1,1,2,3,3-hexachloropropene.

Example 13

285.5 g (1.0 mol) of 1,1,1,2,2,3,3-heptachloropropane and 0.3 g (0.1 mmol) of tetrabutyl phosphonium chloride were charged into a round bottom flask of 500 ml with a Dimroth condenser and a dropping funnel.
With keeping it at 40°C and agitating violently, 250 ml of KOH aqueous solution of 20 % concentration was dropped for 1 hour. After the dropping was finished, the agitating was stopped and a lower organic layer was analyzed. 1,1,1,2,2,3,3-heptachloropropane as a raw material disappeared and the organic layer consisted of only 1,1,1,2,3,3-hexachloropropene.
The reaction solution was transferred to a separatory funnel to separate the organic layer. After washing with a saturated salt solution two times, it was dried with magnesium sulfate to obtain 239 g (96 %) of crude 1,1,1,2,3,3-hexachloropropene.

Example 14

285.5 g (1.0 mol) of 1,1,1,2,2,3,3-heptachloropropane and 0.3 g (0.1 mmol) of trioctylmethyl ammonium chloride were charged into a round bottom flask of 500 ml with a Dimroth condenser and a dropping funnel.
With keeping it at 40°C and agitating violently, 250 ml of KOH aqueous solution of 20 % concentration was dropped for 1 hour. After the dropping was finished, a reaction was advanced for 2 hours. Then the agitating was stopped and a lower organic layer was analyzed. 1,1,1,2,2,3,3-heptachloropropane as a raw material disappeared and the organic layer consisted of only 1,1,1,2,3,3-hexachloropropene.
The reaction solution was transferred to a separatory funnel to separate the organic layer. After washing with a saturated salt solution two times, it was dried with magnesium sulfate to obtain 237 g (95 %) of crude 1,1,1,2,3,3-hexachloropropene.

Comparative example 1

285.5 g (1.0 mol) of 1,1,1,2,2,3,3-heptachloropropane was charged into a round bottom flask of 500 ml with a Dimroth condenser and a dropping funnel.
With keeping it at 40°C and agitating violently, 250 ml of KOH aqueous solution of 20 % concentration was dropped for 1 hour. After the dropping was finished, a reaction was carried out for 3 hours. Then, the agitating was stopped and a lower organic layer was analyzed.
The reaction was carrried out only a little, 63 % of the organic layer consisted of 1,1,1,2,2,3,3-heptachloropropane as a raw material, and the conversion ratio was 37 %.
According to the above-mentioned results, 1,1,1,2,3,3-hexachloropropene can be easily produced by the reaction based on the invention.

Example 15

By reacting under the same condition as that of Example 11 except for the alkali aqueous solution used therein 20 % KOH aqueous solution was changed with 20 % NaOH aqueous solution, 232 g (93 %) of crude 1,1,1,2,3,3-hexachloropropene was obtained.

Example 16

A reaction was carried out under the same condition as that of Example 7 except for charging 29.9 g (0.1 mol) of SbCl₅ and 22.9 g (0.1 mol) of SbCl₃ into a Hastelloy-made autoclave of 500 ml with a condenser.
As a product, 194 g of an organic substance was obtained. It was confirmed with GLC that 98 % of the product was the objective 1,1,1,3,3-pentafluroro-2,3-dichloropropane (93 % of the yield). A main by-product was 1,1,1-tetrafluoro-2,3,3-trichloropropane and a compound added by chlorine was not detected.

Claims

A method of producing 1,1,1,3,3-pentafluoropropane characterized in that 1,1,1,3,3-pentafluoro-2,3-dichloropropane is reacted with hydrogen to conduct a hydrogen reduction under the presence of a noble metal catalyst in gaseous phase.
The production method as defined by claim 1, wherein the noble metal catalyst is carried on at least one kind of carriers selected from active carbon, silica gel, titanium oxide and zirconia.
The production method as defined by claim 2, wherein the carrying concentration of the noble metal catalyst on the carriers is from 0.05 to 10%.
The production method as defined by any of claims 1 to 3, wherein the noble metal catalyst comprises palladium.
The production method as defined by any of claims 1 to 4, wherein at least a stoichiometric amount of hydrogen for 1,1,1,3,3-pentafluoro-2,3-dichloropropane is used for the hydrogenation.
The production method as defined by any of claims 1 to 5, wherein the reaction is carried out at a temperature range from 30 to 450°C.
The production method as defined by any of claims 4 to 6, wherein at least one kind of element selected from zirconium and vanadium is added to palladium.
The production method as defined by any of claims 1 to 7 including the following steps

(1) reacting 1,1,1,2,2,3,3-heptachloropropane with an aqueous solution of an alkali metal hydroxide in the presence of a phase transfer catalyst to obtain 1,1,1,2,3,3-hexachloropropene,

(2) fluorinating said 1,1,1,2,3,3-hexachloropropene with hydrogen fluoride in the presence of antimony trihalogenide and/or antimony pentahalogenide in a liquid phase, wherein the hydrogen fluoride is present in the reaction system in a mole ratio of or over five times that of antimony trihalogenide and/or antimony pentahalogenide, to obtain 1,1,1,3,3-pentafluoro-2,3-dichloropropane, and

(3) reacting said 1,1,1,3,3-pentafluoro-2,3-dichloropropane with hydrogen to conduct a hydrogen reduction under the presence of a noble metal catalyst in gaseous phase.
The production method as defined by claim 8, wherein in step (1) the phase transfer catalyst is a tetraalkyl ammonium salt.
The production method as defined by claim 8, wherein in step (1) the phase transfer catalyst is a tetraalkyl phosphonium salt.
The production method as defined by claim 8, wherein in step (2) 1,1,1,2,3,3-hexachloropropene and hydrogen fluoride as raw materials are supplied into the reaction system and 1,1,1,3,3-pentafluoro-2,3-dichloropropane produced thereby is selected therefrom while the reaction pressure is kept constant.
The production method as defined by any of claims 1 to 7 including the following steps

(1) fluorinating 1,1,1,2,3,3-hexachloropropene with hydrogen fluoride in the presence of antimony trihalogenide and/or antimony penta halogenide in a liquid phase, wherein the hydrogen fluoride is present in the reaction system in a mole ratio of or over five times that of antimony trihalogenide and/or antimony pentahalogenide, to obtain 1,1,1,3,3-pentafluoro-2,3-dichloropropane, and

(2) reacting said 1,1,1,3,3-pentafluoro-2,3-dichloropropane with hydrogen to conduct a hydrogen reduction under the presence of a noble metal catalyst in gaseous phase.
The production method as defined by claim 12, wherein in step (1) 1,1,1,2,3,3-hexachloropropene and hydrogen fluoride as raw materials are supplied into the reaction system and 1,1,1,3,3-pentafluoro-2,3-dichloropropane produced thereby is selected therefrom while the reaction pressure is kept constant.
The production method as defined by any of claims 1 to 7, wherein said 1,1,1,3,3-pentafluoro-2,3-dichloropropane is obtained by a method including the following steps

(1) reacting 1,1,1,2,2,3,3-heptachloropropane with an aqueous solution of an alkali metal hydroxide in the presence of a phase transfer catalyst to obtain 1,1,1,2,3,3-hexachloropropene, and

(2) fluorinating said 1,1,1,2,3,3-hexachloropropene with hydrogen fluoride in the presence of antimony trihalogenide and/or antimony petahalogenide in a liquid phase, wherein the hydrogen fluoride is present in the reaction system in a mole ratio of or over five times that of antimony trihalogenide and/or antimony pentahalogenide, to obtain 1,1,1,3,3-pentafluoro-2,3-dichloropropane.